摘要
Recent ce-valuation of the dating of the carbonatite dykes associated with the REE-Re-Nb giant deposit at Bayan Obo
Recent re-valuation of the dating of the carbonatite dykes associated with the REE-Fe-Nb giant deposit at Bayan Obo has revealed an anomaly with one of the dates. Inspection of the post-1990 literature for the carbonatite dykes and H8 dolomite rocks and ores of Bayan Obo provides age data in the range 1223±65 Ma to 1656 Ma, as Table 1 shows. Since Sm and Nd are relatively immobile elements, most of the Sm-Nd dates are considered to be little changed by the subsequent mineralization processes. That the dates occur in two clusters, 1656 - 1500 Ma and 1312 - 1223 Ma might refer to two related periods of carbonatitic magmatic activity, but that is not relevant at this moment.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第2期517-518,共2页
Acta Petrologica Sinica